The utility model discloses a fixing device of outer glass bulb of mercury vapor lamp and lamp holder has solved the mercury vapor lamp during operation and has generated heat, makes glue melt the problem that leads to outer glass shell and lamp stand to drop sometimes. Its characterized in that: the circumference wall equipartition of tip has a plurality of concave points or salient point under the outer glass bulb, lamp holder top circumference equipartition has a plurality of axially extended fixed strips of lamp holder of following, be equipped with concave point or salient point matched with salient point or concave point with outer glass bulb on the fixed strip. The utility model discloses a salient point or concave point are mutually supported on outer glass bulb fovea superior dot OR salient point of mercury vapor lamp and the fixed strip, make the lamp holder fix outer glass bulb, and when guaranteeing that mercury vapor lamp work is generated heat, outer glass shell can not take place the obscission with the lamp holder.